Packing and power transmission unit



April 23, 1940. P. s. BALDWIN 2,197,915

PACKING AND POWER TRANSMISSION UNIT F'iled'sept. 20, 1958 Patented` Apri. -19,40

UNITED u' STATES VPATENT l OFFICE l v 2.197,91; rAoxmG AND rowEn TRANSMISSION UNI'r Philip Sidney Baldwin, Florence, Italy Application .September 20, 1938, Serial No. 230,890

1s claims.

'I'his invention relates to improvements in the structure of the packing and power transmitting units shown in my application Serial No. 125,341,v filed February 1l, 1931'.l

5 Difficulties have been encountered in moulding the unit in one piece, and while it is possible to do so, it has been found that a unit` built upf several interiitted parts presents less dimculty and is equally satisfactory. One'of the objectsJ of this invention is to'provide such ta unit built y up of a number of separately moulded parts which will be held together and operate as a unit 'under uid pressure.

It has been found that-the fluid under pressure could be more quickly and easily directed around the effective radial surface of the unit to the space :behind the lips by providing ymeans -for guiding the iiow of the fluid to said lips. This permits the fluid to be readily discharged from the unit and prevents it being trapped behind the lips upon release of pressure. A further object of this invention, therefore, is to provide such guiding means for the unit.

Still a further object of this invention is to secure application of the uid pressure simultaneously on the effective radial surface of the unit even though the unit is under axial mechanical compression, and-not progressively fro'm the center outwards towards the lips as would be the case were iiuid guiding means not provided. This permits the unit simultaneously to contract radially and extend axially on the protractile stroke, and tocontract axially andexpand radially on the retractile stroke; the interfitted parts being clinched together under radial fluid pressure to expand and contract as a unit.

For a more complete understanding of the invention, reference ls made to the accompanying drawing, illustrating several forms of the inven-I tion. All like reference characters refer to like parts throughout the several views.

Figure 1 is a central vertical sectional view of the improved unit,

Figure2 is a central horizontal section thereof,

Figure 3 is a central vertical section showing the unit of Figure 1 incorporated in the wheel cylinder of a hydraulic brake,

Figure 4 is a side elevation of one of the cap (ci. 30s-31') from the wau 4. The external wan 4 of the unit is provided with a circumferential recess 5 which may be placed at any point on said wall between the lips ateach end of the body, but is prefer-y ably arranged centrally betweenthe spacedlips 5 as shown in the drawing. A series of channels 6, axially disposed, are formed around the entire external wall of the`unit, intercommunicating with and. extending from the recess 5 to the spaces 3 behind the lips 2. Thus, when fluid l0 under pressure isintroduced into conduit I and wheel cylinder 8, it flows directly linto recess 5 and immediately surrounds the unit, flowing from the -recess?, through channels 6 and into spaces A 3, pressing lips 2 against the cylinder wall 9 to l5 'form a fluid-seal. Pressure then takeseifect radially against the body ofthe unit, as described in my Patent No. 2,048,771,\distending and elongating'it in anf-axial direction to actuate the brake slices (not shown); By "means of the 20 recess 5 `and channels 6 the fluid is distributed more quickly and evenly around the unit; so that pressure can take effectsubstantially simultane- I ously around the entire 'outside wall i which is the eiective radial surface of vthe element, clinch- 25- ing the component parts of the unit together and causing them to expand and contract as a unit. Were fluid pressure not distributed simultaneously over the radial surface 'as described but progressively from the centre outwards, the plug 30 portions I5 and I5a of the cap members would be forced out of their respective sockets and fluid would be trapped in the body of the unit.

In the form of unit shown in Figure 1, the device is of a three piece construction. In this 35 form, the body I has oppositely disposed sockets, Il, IIa moulded in the ends, and these sockets are separated byy a partition I2. Ca members- I3, I3a, respectively, are seated in the e sockets. The cap members have enlarged portions I4, Ida, o respectively, and reduced plug portions I5, I5a, respectively, Athe plug portions extending into and frlctionally' engaging the entire surface of the walls of their respective sockets. In all forms of the invention, the flt of `the plugs 'in the 45 sockets should be so close asto force out the air therein when the plug is inserted, and this can be accomplished by twisting the plug as it is inserted. In the finished element, the fltis so close as to require considerable force to dislodge v the plug from the socket against the suction created therein by a direct outward pull. 'The enlarged portion of each cap member is seated on the mouth of the socket, as shown, and each cap has a skirt or lip 2 which overhangs the B6 l of rubber, rubber substitutes, or other suitable resilient elastic material.

In the modiiied form shown in Figure 5, the sockets Il, Ila are made bulbous-like, and the plug portions of the cap members are made of corresponding shape and size to secure a good friction lit between the parts. In this form, the lip 2 is not oiset from the outside wall 4, the waist portion or outside wall of the unit being designed to have a closer ilt in its cylinder container. y y D The unit is designedfto be mechanically compressed axially in its cylinder container. In Figure 4 it is compressed under tension of thebrake shoe return spring (not shown). tension causes the unit to expand radially and plug the cylinder around the two ends of the cap members and positively prevents air being drawn into the cylinder at these points. Obviously, fluid pressure applied to the unit ltakes effect directly on the annular end surfaces of the lips and, were the unit not under mechanical compression, would force the lips outwards with the opposed Ypistons before iluid pressure could take effect on vthe radial surface of the element. 'I'he mechanical pressure resists this direct axial fluid pressure and permits the fluid pressure to be initially built up on the'element radially to extend it axially as described.

Changes may be made in the construction without departing from the scope of the invention as defined by the appended claims.

Having thus described my invention, I claim:

l. A packing and power transmitting unit for hydraulic systems comprising a resilient body having a wall, a fluid sealing lip on said unit projecting over said wall, said unit having a iiuid receiving space behind said lip to accommodate a iiow of uid between said lip and wall, and means in said wall, extending behind said lip, for guiding uid under pressure along the wall to said space.

2. A packing and power transmitting unit for hydraulic systems comprising a. resilient body having a wall, a fluid sealing lip on said unit projecting over said wall, said unit having, a uid receiving space behind said lip to accommodate a iiow of iiuid between said lip and'wall, and channels in said wall, extending into said space,

for guiding uid under pressure along the wall to having a wall, a uid sealing lip on said unitprojecting over said wall at each end thereof, said unit having a uid receiving space between each lip and wall to accommodate a flow of fluid between each lip and wall, and means in said wall, extending to said lips, for guiding uid under pressure along the wall to said spaces.

5. A packing and power transmitting unit for hydraulic systems comprising a resilient body, said body having a wall with spaced iiuid sealing lips projecting over said wall, said unit having a This initial fluid receiving space behind each lip to accommodate a flow of fluid between said lip and wall, a recess in said wall between said lips, and means on said wall, extending from said recess to said lips, forguiding iluid under pressure along said wall to said spaces. I

6. A packing and power transmitting unit for hydraulic systems comprising a resilient body having a cylindrical wall with spaced fluid sealing lips projecting over said wall, said unit having iiuid receiving spaces behind said lips to accommodate a iiow of i'luid between said lips and wall, an annular'recess in said wall between said lips, and means on said wall, extending from said recess to said lips, for guiding uid under pressure along said wall to said spaces. 7,.. A packing and power transmitting unit for hydraulic systems comprising a` resilient-'body having a socket at each end thereof and a resilient cap member for each socket, each cap member having an enlarged portion and a re,

duced plug portion, said plug portion extending into and frictionally engaging the wall of its corresponding socket, said enlarged portion extending above the upper edge of the socket and having a lip overhanging the external wall of the resilient body, said Alip being spaced from the body s so as to provide a space between the lip and Wall to accommodate a flow of fluid therebetween.

8. A packing and power transmitting unit for hydraulic systems comprising a resilient body having a socket at each end thereof and a resilient cap" member for each socket, each cap member having an enlarged portion and a reduced plug portion, said plug portion extending into and frictionally engaging the wall of its corresponding socket, said enlarged portion extending above the upper edge of the socket and having a 'lip overhanging the external wall of the elastic wall, said lip being spaced from said external wall so as to provide a space between the lip and wall to accommodate a flow 4of fluid therebetween, and means on said body extending to eachv lip, for guiding iiuid under pressure along said wall to said spaces.

9. A packing and power transmitting unit for hydraulic systems comprising a resilient body having a socket at each end thereof and a resilient cap member for each socket, each cap member having an enlarged portion and a reduced plug portion, said plug portion extending into and frictionally engaging the wall of its corresponding socket, said enlarged portion extending above the upper edge of the socket and having a lip overhanging the external wall of the resilient wall, said lip being spaced from said external wall so as to provide a space between the lip and wall to accommodate a flow of fluid therebetween, and ribs on said Wall extending longitudinally thereof to each lip for guiding fluid under pressure to said space.

10. A packing and power transmitting unit for hydraulic systems comprising a resilient body having a socket at each end thereof and a resilient capmember for each socket, each cap member having a plug portion extending into and frictionally engaging the wall 0f its socket, and a. portion extending above the upper edge of each socket and having a lip overhanging the external wall of the resilient body, said lip being spaced from said external wall so as to provide a 'space between the lip and wall to accommodate a flow of fluid therebetween,.a recess in the wall of said body and means on said wall extending from said u recess to each lip, for guiding iiuid under pressure along said wall to each space.

11. A packing and power transmitting unit for hydraulic systems comprising a resilient body having 'bulbous-like sockets at each end thereof,

and a. resilient cap member for each socket, each 'cap member having an enlarged portion of a diameter substantially coextensive with the external diameter of the body, and a reduced bulbous-like plug portion, said plug portion extending into and frictionally engaging the wall of its corresponding socket, the enlarged portion being seated on the end of the body, said enlarged portion having a -lip overhanging said wall providing a. space between said lip and wall to accommodate a flow of fluid therebetween.

12. A packing and powertransmitting unit for hydraulic systems comprising a resilient body having a wall, a uid sealing' lip on said unit vprojecting over said wall', said unit having a iiuid receiving space behind jsaid lip, iiuid guiding means arranged around said wall, and means on said wall connecting said'iuid4 guiding means with said space, for guiding uid from said first mentioned means to said space.

13. A packing and power transmitting unit adapted to be compressed radially and extended axially in a hydraulic system, comprising a resilient body having a wall, a sealing lip'on said unit overhanging said wall and spaced therefrom to provide a iluid receiving space behind said lip to accommodate a iiow of. fluid/between said lip and body, and means formed in said wall for guiding .iluid under pressure to said space.

Pima? SIDNEY BALDWIN. 

